Skull


  • Upper end of the vertebral column and it's bony structure is devided in to two part

  1. The Cranium
  2. The Face


  • Cranium


Formed by a number of flat and irregular bones that protect the brain .
Sutures joint in the skull the bone are immovable
Periosteum lining in inner surface

  • Bones of cranium

  1. Frontal bone 
  2. Parietal bone (pair)
  3. Temporal bone (pair)
  4. Occipital bone
  5. Sphenoid bone
  6. Ethmoid bone




Frontal Bone

  • Bone of the forehead
  • It forms part of the orbital cavities (eye socket) and the promint ridge above the eye , the supraorbital margins .
  • Two aif filled cavities or sinus lined with ciliated mucous membrane , which opne in to the nasal cavity .
  • The coronal suture joint the frontal and parietal bone and other suture are formed with the sphenoid , zygomatic , nasal , ethmoid and lacrimal bones .




Parietal Bone

  • Sides and roof of the skull
  • They articulate with each other at the sagittal suture with the frontal bone at the coronal suture , with the occipital bone at the lambdoidal suture and with the temporal bones at the squamous suture .
  • The inner surface is concave and is grooved to accommodle the brain and blood vessels .


Temporal Bone

  • The squamous part is the thin fan snapped
  • Squamous part articulate with parietal bone
  • Zygomatic process articulate with zygomatic bone
  • Temporal bone articulate with the mandible at the temporomandibular joint .
  • Styloid process projects from the lower process of the temporal bone , and supports the Hyoid bone and muscle associated with the tongue and pharynx


Occipital Bone

  • Back of the head
  • Suture with parietal , temporal and sphenoid bones
  • Two articulate condyles that form condyloid joint with the first bone of vertebral column (Atlas)
  • The joint permits nodding movement of the head


Sphenoid Bone

  • Middle portion
  • Articulate with occipital , temporal , parietal and frontal
  • Hypophyseal fossa in which the pituitary gland rest


Ethmoid Bone

  • Anterior part
  • Help to the orbital cavity
  • The nasal septum and the lateral walls of the nasal cavity

  

Face

  1. Zygomatic (Cheek)      2 Bone
  2. Maxilla                         1 Bone
  3. Nasal bone                   2 bone
  4. Lacrimal bone.             2 bone
  5. Vomer.                          1 bone
  6. Palatine bone.               2 bone
  7. Inferior conchae            2 bone
  8. Mandible.                      1 bone


Zygomatic bone

  • Part of the floor and lateral wall of the orbital cavities


Maxilla (Upper jaw bone )

  • 2 bone that fuse before birth
  • Anterior part of the roof of the mouth , the lateral walls of the nasal cavity and of the floor of the orbital cavity


Nasal Bone

  • Two small flat bone
  • That from the greater part of the lateral and superior surface of the bridge of the nose.


Lacrimal Bone

  • Two small bone
  • Posterior and lateral to the nasal bone from part of the medial wall of the orbital cavity.


Vomer

  • Thin flat bone
  • Middle of the hard palate to form most of the inferior part of the nasal septum
  • Superiorly it articulate with the perpen dicular plate of the ethmoid bone


Palatine bone

  • Two small L-Shaped bone
  • Posterior part of the hard palate and the perpendicular parts project upwards to form part of the lateral walls of the nasal cavity
  • Their upper extremities they form part of the orbital cavities .


Inferior Conchae

  • Scroll-Shaped
  • Part of lateral wall of the nasal cavity
  • The superior and middle conchae are parts of the ethmoid bone
  • The conchae collectively increase the surface air to be warmed and humidified more effectively



Mandible ( lower Jaw bone )

Only movable bone of the skull
Two main part
1) Curved body with the alveolar ridge containing the lower teeth
2) Ramus almost at right angles to the posterior end of the body

  • Ramus divides in to the condylar process which articulate with the temporal bone to form the temporomandibular joint
  • The coronoid process which gives attachment to muscle and ligament that close the jaw.


Hyoid bone

  • Horseshoe (U) Shaped
  • Neck just above the larynx and below the mandible .
  • It does not articulate with any other bone but is attached to the styloid process of the temporal bone by ligament
  • It supports the larynx and give attachment to the base of the tongue .